This invention relates to an improved ski design and more particularly to a ski design with a reverse camber bottom surface.
It is reported that the first skis were made of barrel staves. Because of the lateral and longitudinal curvature of the staves, skiers had difficulty controlling direction of ski movement and turns. Subsequently, ski poles were developed which the skier could use to place in the ground and thereby steer himself.
Skis were then developed with a groove along the middle of the bottom of the ski to improve ski stability and permit the skier to ski in a straight line. Skis of this type were generally flat. Later, skis were constructed with a bottom surface that bowed slightly upward at the center. This structure provided improved ski stability. The upwardly bowed shape of the bottom ski surface is termed "camber". Clement, U.S. Pat. No. 2,258,046, issued Oct. 7, 1941 for a Ski, illustrates an early ski which incorporates camber.
Subsequently it was discovered that by making the forward end and rear end of the ski wider than the center or waist of the ski, ski stability and ease of turning would improve. Beerli, in U.S. Pat. No. 2,510,794 issued June 6, 1950, illustrates this concept which is termed "side camber". In recent years improved materials have been used for the manufacture of skis to provide improved stability and consistency in skis. Other related developments in the art of skis are represented by U.S. Pat. No. 3,212,787 issued Oct. 19, 1965 to L. R. Werntz for a Snow Ski For Making Fast Turns. This patent illustrates a ski which has a flat surface with vertical, downwardly projecting blades running from a position beneath the ski boot binding to the rear end of the ski. The front of the ski is elevated with respect to the horizontal surface at the rear half of the ski.
Sarver U.S. Pat. No. 4,085,947 and Sarver U.S. Pat. No. 4,007,946 both teach a raised or elevated planar section forward of the binding. Both of these patents, however, also teach a ski which has a very short trailing edge at the rear of the ski binding.
Despite the numerous improvements in ski design, skiing remained difficult to learn for many. To overcome this difficulty, a new learning technique was developed known as the graduated length method (GLM). This method to teach skiing starts by providing short skis, approximately 3' long, for the beginning skier. As the skier becomes more and more proficient, he graduates to a longer and longer ski until ultimately the traditional ski, which is about 6' long, is mastered by the student.
Although the graduated length method has proven to be an excellent teaching tool, the short ski used in the teaching method created an uneven pattern of closely spaced moguls or valleys and hillocks on a ski slope which would interfere with the safe and efficient operation of normally sized skis. Normal skis, which are longer and more flexible than the short skis, often break or dig into snowbanks when used on a slope with moguls created by GLM skis. Therefore, the need for a long instructional ski has been sought. Such a ski would be useful in teaching the beginning skier, yet it would not create an undesirable pattern of moguls on a ski slope.